So Donald Trump is to be the Republican Party nominee. Establishment Republicans need to take a deep breath: The U.S. system of checks and balances was designed to preclude the kind of tyranny some are warning could accompany a Trump presidency. There will not be guillotines in the streets of Washington. Nonetheless, establishment Republicans are right to be shocked: Until recently, ours has been a strikingly successful political party. The Republicans’ governing wing holds majorities in the U.S. Senate, House of Representatives, state legislatures, and governorships. Under President Barack Obama, Democrats have lost 13 seats in the Senate, 69 seats in the House, over 900 seats in state legislatures, and 12 governorships. It looks like their losing streak may be ending.

Republican elites need to acknowledge that significant numbers of voters in our own party support a candidate who does not subscribe to orthodoxy on foreign policy, trade, immigration, and many other matters. Republicans need to prepare for a landslide defeat at the hands of a candidate who has alienated a substantial majority of the country. But we also need to prepare for the possibility that, just was we were all wrong about Trump’s prospects of winning the Republican nomination, we might also be wrong about his strength against Hillary Clinton. There is a scenario in which Trump could channel the anger not only of his own voters, but of those who have supported Bernie Sanders, in ways that could actually produce victory in November. This is not a reason to vote for him, but it is a warning.